Two filtering algorithms—spin filter and binary spin filter—suitable for various digital interferometric images are presented in this paper. Both can filter out the noise in the interferometric patterns without distorting the fringe features, whereas other commonly used filters, such as median filter and FFT passband filter, may blur the patterns. A process for automatically extracting fringe centerlines all over the field is also proposed. This is done by using the spin filters mentioned above together with the derivative binary image. The effectiveness of this technique is illustrated experimentally.
© 1988 Optical Society of AmericaPDF Article